Hey Scotty!
I suspect 1-2 hours should be enough spacing between the Carb/Protein and Fat/Protein meals. Insulin sensitivity appears to be improved to such a degree on IF that this may or may not be necessary but it makes good sense. I have noticed this scenario actually makes IF easier in that the C/P meal makes me hungry quicker than a F/P meal. This makes it easier to sneak in subsequent meals.